RIVERS (UK BAP PRIORITY HABITAT)
Summary
This priority habitat encompasses a broad range of running water types including small, fastflowing headwaters and low level deep meandering rivers near the sea. It excludes canals
and ditches.
The vegetation associated with rivers varies depending on the underlying geology, water
quality, flow, and habitat features. Generally the upper, faster-flowing reaches of rivers are
dominated by bryophyte communities, whilst higher plants are more typical of lower reaches.
Rivers flow through a wide range of habitats. More natural examples may be linked to areas
of wet woodland, marshy grassland, swamps and reedbeds.
Good management for conservation of rivers usually focuses upon maintaining or improving
water quality, limiting modifications to banks and channel flow, and enabling connectivity
between the river and its floodplain. Rivers may also be managed for the important species
that they support.
What is it?
The Rivers Priority Habitat encompasses a broad range of natural or near-natural river types
from small, fast-flowing headwaters, to low level meandering rivers near the sea. The
definition of this priority habitat is based on river lengths, or „water bodies‟ defined for use in
the EC Water Framework Directive (WFD). These may not necessarily comprise single
rivers but may also include several streams within the catchment or sub-catchment. Whilst
not all headwaters are defined as water bodies for the WFD, owing to their small catchment
size, they can be defined as UKBAP priority habitat. Only habitat present between the bank
tops is considered within the definition; adjoining habitats that may be an integral part of the
ecological unit (e.g. floodplain woodland) are excluded.
To qualify as priority habitat the water body must meet one of the following criteria:

Rivers of high hydromorphological/ecological status. These are identified using
criteria developed for the purposes of the WFD
http://www.wfduk.org/tagged/river.

Headwaters - defined as „a watercourse within 2.5 km of its furthest source as
marked with a blue line on Ordnance Survey (OS) Landranger maps with a scale
of 1:50,000‟ (Furse, 1995).

Presence of the EC Habitat Directive Annex I habitat - water courses of plain to
montane levels with the Ranunculion fluitantis and Callitricho-Batrachion
vegetation (including, but not limited to, all sites designated as SACs for this
feature).

Chalk rivers – these do not occur in Scotland.

Active shingle rivers - dynamic river channels, which frequently change course
and are undergoing active erosion and deposition. Visually they are recognized
by having significant lengths of gravel or pebble substrates which are partially
exposed during normal flow. Scotland supports some “classic” examples of this
type of river, of which the best known is the River Feshie.

River Sites of Special Scientific Interest (SSSIs), which have been designated for
riverine features, fluvial geomorphology or because they support species
restricted to river habitats – Scotland has relatively few River SSSIs (around 20).

Presence of important species – these are defined as Annex II Habitats Directive
species; BAP priority species; and invertebrate species which are strongly
indicative of river shingle. Species have been categorised according to their
dependence on river habitat quality. The presence of a single species highly
dependent on river habitat quality, or the presence of 6 or more species less
dependent on river habitat quality is required to qualify as priority habitat. The
species are listed in Annex 1 to the UK BAP priority habitat description for rivers
http://jncc.defra.gov.uk/page-5706.
The Rivers priority habitat can occur on all geology and soil types. It includes rivers of all
flow types, at all altitudes.
In addition to the permanently wetted main river channel, the river category includes
marginal areas that are periodically inundated; rocks and boulders which are located within
the river channel, but which extend above the water surface to create “splash zone areas”;
and features created by erosion and deposition such as exposed cliffs and bars.
Micro-habitats in the channel are created by variations in flow; broken waves and riffles help
to oxygenate the water, whilst deep pools are used for resting by fish species. Bankside
vegetation also influences habitat: exposed tree roots below the water surface are valuable
for fish spawning, and shade from trees is important. Exposed sediments such as shingle
and sand bars are important for a range of invertebrates, notably ground beetles, spiders
and craneflies. Marginal and bankside vegetation acts as habitat in its own right and as a
migration corridor.
Water quality (mainly nutrient levels and the acidity or alkalinity of the water), flow rate and
substrate have strong influences on the animals and plants present in a river. Upland rivers,
which tend to have rocky substrates and fast water flow are dominated by mosses and
liverworts and support few higher plants. The invertebrate fauna is dominated by species of
stonefly, mayfly and caddisfly. The lower reaches of rivers are characterised by slower
flows, with greater numbers of higher plants. These areas tend to support greater amounts
of marginal and bankside vegetation. The invertebrate fauna includes higher numbers of
worms, dragonflies and damselflies. Coarse fish species (e.g. pike Esox lucius, dace
Leuciscus leuciscus and roach Rutilus rutilus) are also more common in the lower reaches.
How do I recognise it?
Differentiation from other Priority Habitats
Ponds created as a result of river dynamics (e.g. oxbow lakes), are included within the
Rivers priority habitat. By contrast, ponds that are artificial, or have been formed by a
process unrelated to river dynamics, form a separate priority habitat type.
Other water-dependent habitats (e.g. fen, wet woodland), may occur in close proximity to
rivers. Whilst these may form an integral component of river systems for conservation and
management purposes, they are excluded from the definition of the Rivers priority habitat.
Habitats and communities of river shingle are also excluded from the definition of river
priority habitat.
Definition in relation to other habitat classifications
Classification scheme
JNCC River Types
NVC Aquatic communities
NVC Swamps and tall-herb fens
Phase 1
UKBAP Broad Habitat
Relationship with UK priority habitat: Rivers
Includes examples of all types I – X.
The UK BAP habitat description lists: A2, A8-9,
A11-20, but only A8, A9, A11, A13 – A20 are
found in Scottish rivers. A5 and A10 may also be
found in Scottish Rivers.
The UK BAP habitat description lists: S4-9, S1114, S16-19, S22, but only S11, S12, S14, S19
and S22 are found in Scottish rivers. S26 and
S28 may also be found in Scottish rivers.
G2 Running Water
All examples of this priority habitat are
associated with the broad habitat - Rivers and
streams.
Definition in relation to legislative classifications
Classification scheme
Annex I:
Scottish Biodiversity List
SSSI habitat features
Relationship with UK priority habitat: Rivers
Includes all examples of H3260 Water courses of
plain to montane levels with the Ranunculion
fluitantis and Callitricho-Batrachion vegetation
NVC categories: A5, A9-11, A14, A16-20, S4,
S26, S28; Unvegetated freshwater habitats; Tree
roots in freshwater aquatic habitats
Whole rivers or sections of rivers can be selected
to represent each of the ten broad JNCC River
types (I – X).
Where is it?
Scotland has about two-thirds of the main river systems in Great Britain (Usher, 2000), which
encompasses a varied river resource.
What is special about it?
Some species of special conservation status recorded in this priority habitat in Scotland are
listed below. Species not native in Scotland (e.g. Floating water-plantain Luronium natans)
have been excluded from the Table.
Group
beetle
beetle
Com mon
nam e
pale pin-palp
minutest
diving beetle
beetle
beetle
shingle rove
beetle
bird
marsh w arbler
bird
reed bunting
common
grasshopper
w arbler
bird
bird
yellow wagtail
bird
kingfisher
small grey
sedge
marsh
clubmoss
Scottish
yellow splinter
river-shore
cranefly
w hite-clawed
crayfish
marsh
clubmoss
common
sturgeon
allis shad
tw aite shad
European eel
river lamprey
brook lamprey
smelt
(sparling)
sea lamprey
Atlantic
salmon
brow n trout
Arctic charr
haw kweed
groups
caddisfly
clubmoss
cranefly
cranefly
crustacean
fern
fish
fish
fish
fish
fish
fish
fish
fish
fish
fish
fish
flow ering
plant
flow ering
plant
flow ering
plant
flow ering
plant
flow ering
plant
flow ering
coral-necklace
tubular w aterdropw ort
grass-wrack
pondw eed
Shetland
pondw eed
greater w ater
Latin nam e
Bembidion testaceum
Bidessus
minutissimus
Dyschirius angustatus
Meotica anglica
Acrocephalus
palustris
Emberiza schoeniclus
Locustella naevia
Motacilla flava subsp.
flavissimia
Alcedo atthis
Glossosoma
intermedium
UK BAP
priority
list
y
EC
Habitats
Directive
Annex II,
IV or V
y
Birds
Directive
Schedule
I or II
Scottish
Biodiversity
List
Red
Data
List
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
Lipsothrix ecullata
y
y
y
y
y
y
y
y
Lycopodiella inundata
Acipenser sturio
y
y
Lycopodiella inundata
Rhabdomastix
japonica
Austropotamobius
pallipes
Wildlife
and
Countryside Act
(1981)
y
y
y
y
y
y
y
Alosa alosa
Alosa fallax
Anguilla anguilla
Lampetra fluviatilis
Lampetra planeri
Osmerus eperianus
y
y
y
y
y
y
y
y
y
y
y
y
y
Petromyzon marinus
Salmo salar
y
y
y
y
y
y
Salmo trutta
Salvelinus alpinus
Hieracium sect.
Alpestria
Illecebrum
verticillatum
y
y
Oenanthe fistulosa
y
Potamogeton
compressus
y
Potamogeton rutilus
y
Sium latifolium
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
Group
plant
flow ering
plant
fly
fly
fly
lichen
lichen
lichen
liverw ort
mammal
mammal
mammal
mammal
mammal
mayfly
mollusc
moss
moss
moss
moss
moss
stonefly
Com mon
nam e
parsnip
marsh
stitchw ort
southern silver
stiletto fly
northern
yellow splinter
southern
yellow splinter
river jelly
lichen
ear-lobed doglichen
a lichen
Dumortier‟s
liverw ort
w ater vole
otter
Daubenton‟s
bat
noctule
soprano
pipistrelle
iron blue
mayfly
freshwater
pearl mussel
snow rockmoss
round-leaved
bryum
cernuous
bryum
Scottish pohlia
scarce turfmoss
northern
february red
Latin nam e
UK BAP
priority
list
EC
Habitats
Directive
Annex II,
IV or V
Birds
Directive
Schedule
I or II
Scottish
Biodiversity
List
Red
Data
List
Wildlife
and
Countryside Act
(1981)
Stellaria palustris
y
y
Cliorismia rustica
y
y
Lipsothrix errans
y
Lipsothrix nervosa
y
Collema dichotomum
y
y
y
y
Peltigera lepidophora
y
y
y
y
Phaeophysicia
endococcin
y
y
y
Dumortiera hirsuta
y
y
y
Arvicola terrestris
Lutra lutra
y
y
y
y
y
Myotis daubentonii
y
y
y
y
y
Nyctalus noctula
y
y
y
y
Pipistrellus pygmaeus
y
y
y
y
Nigrobaetis niger
y
Margaritifera
margaritefera
y
y
y
y
Andreaea nivalist
y
y
y
Bryum cyclophyllum
y
Bryum uliginosum
y
Pohlia scotia
Rhytidiadelphus
subpinnatus
y
Brachyptera putata
y
y
y
y
y
y
y
y
y
How do we manage it?
Management activities that affect rivers vary between upland and lowland, rural and urban
areas. Unlike most habitats, it is difficult to „lose‟ rivers completely, although they may be
significantly modified or even diverted. Rivers can be managed both directly (e.g. through
channel restoration), or indirectly (e.g. as a result of changes to surrounding land use).
Upland rivers in some parts of Scotland have been vulnerable to acidification of the
catchment, either as a result of changing land use (e.g. planting of introduced conifer
species) or as a result of acid deposition. This can lead to a reduction in water quality, los s
of acid-vulnerable species, and reduced spawning success of salmon and trout (see
http://www.jncc.gov.uk/pdf/Article17/FCS2007-H3260-audit-Final.pdf for further details).
Grazing pressure in upland catchments can lead to localised damage of river banks, and
increased sediment loads. In addition to habitat loss, this may contribute to increased flood
risk.
River channels may be modified as a result of management to reduce flood risk, improve
drainage on agricultural land or create new areas of productive land. Channelisation – which
results in straightening, deepening and/or widening of a river channel has resulted in
downgrading of ecological quality in some areas, and reduced the length of river in lowland
areas as a result of removing meanders.
Rivers are also at risk from invasive non-native species, which are readily transported
between water bodies. For example, invasive plants found in river margins and along river
banks such as Giant hogweed Heracleum mantegazzianum, outcompete native plant
species and the North American Signal Crayfish Pacifastacus leniusculus undermines
riverbanks through burrowing and has a negative effect on native crayfish, fish and aquatic
invertebrates.
Rivers play an important role in providing water for industry, agriculture and drinking. They
also provide an important waste disposal function and elevated levels of nutrients, silt, and
chemicals can impact upon quality. The WFD requires the creation of a river basin planning
system which will promote sustainable water use whilst protecting and improving the water
environment. River Basin Management Plans form a key element, which will include
provision for reducing the impacts of urban and agricultural land management upon the beds
and banks of rivers and bankside vegetation.
References, Links and Further Information
Boon, P.J. et.al. 1996. SERCON: System for Evaluating Rivers for Conservation. Version 1
Manual. Scottish Natural Heritage Research Survey and Monitoring Report No. 61. Perth,
Scottish Natural Heritage. http://www.snh.org.uk/pdfs/publications/research/61.pdf
European Commission DG Environment. 2003. Interpretation manual of European Union
habitats version EUR25. Brussels, European Commission DG Environment.
http://ec.europa.eu/environment/nature/legislation/habitatsdirective/docs/2007_07_im.pdf
Furse, M.T. 1995. The faunal richness of headwater streams: Stage 4 – development of a
conservation strategy. R and D Note 455. Bristol, National Rivers Authority.
http://nora.nerc.ac.uk/502424/
Hatton-Ellis, T. Grieve, N. and Newmand, J. 2003. Ecology of watercourses characterised by
Ranunculion fluitantis and Callitricho-Batrachion vegetation. Conserving Natura 2000 rivers,
Ecology series No 11. Peterborough, English Nature.
http://ec.europa.eu/environment/life/project/Projects/index.cfm?fuseaction=home.showFilean
drep=fileandfil=SMURF_Ranunculus.pdf
Holmes, N. 1983. Typing British Rivers according to their flora. Nature Conservancy
Council, Shrewsbury. (Focus on nature conservation, No 4.) NB: this is the original 1983
NCC classification for rivers, which is now out of print.
Holmes, N.T, Boon, P.J., and Rowell, T.A. 1999. Vegetation communities of British rivers –
a revised classification. Peterborough, JNCC. http://jncc.defra.gov.uk/page-2619
Holmes, N.T.H., Boon, P.J. and Rowell, T.A. 1998. A revised classification system for British
rivers based on their aquatic plant communities. Aquatic Conservation: Marine and
Freshwater Ecosystems, 8: 555-578.
JNCC. 1989 and updates. Guidelines for the selection of biological SSSIs. JNCC.
Maddock, A. (Ed). 2008. UK Biodiversity Action Plans Priority Habitat Descriptions. Rivers.
Updated July 2010. JNCC, Peterborough http://jncc.defra.gov.uk/pdf/UKBAP_BAPHabitats45-Rivers2011.pdf
Usher, M.B. (Ed.). 2000. Action for Scotland's Biodiversity. Edinburgh, The Scottish
Executive and The Stationery Office.
Averis, A.B.G., Genney, D.R., Hodgetts, N.G., Rothero, G.P. and Bainbridge, I.P.
(2012). Bryological assessment for hydroelectric schemes in the West Highlands –
2nd edition. Scottish Natural Heritage Commissioned Report No.449b
http://www.snh.org.uk/pdfs/publications/commissioned_reports/449b.pdf